Methods and Apparatus for Surgical Planning

ABSTRACT

Methods and apparatus for enhancing surgical planning provide enhanced planning of entry port placement and/or robot position for laparoscopic, robotic, and other minimally invasive surgery. Various embodiments may be used in robotic surgery systems to identify advantageous entry ports for multiple robotic surgical tools into a patient to access a surgical site. Generally, data such as imaging data is processed and used to create a model of a surgical site, which can then be used to select advantageous entry port sites for two or more surgical tools based on multiple criteria. Advantageous robot positioning may also be determined, based on the entry port locations and other factors. Validation and simulation may then be provided to ensure feasibility of the selected port placements and/or robot positions. Such methods, apparatus, and systems may also be used in non-surgical contexts, such as for robotic port placement in munitions diffusion or hazardous waste handling.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of prior patent application Ser. No.14/041,017 filed on Sep. 30, 2013 (now U.S. Pat. No. 9,532,838), whichis a continuation of prior patent application Ser. No. 13/432,305 filedon Mar. 28, 2012 (now U.S. Pat. No. 8,571,710), which is a continuationof patent application Ser. No. 11/677,747 filed on Feb. 22, 2007, (nowU.S. Pat. No. 8,170,716), which is a divisional of application Ser. No.10/165,413 filed on Jun. 6, 2002, (now U.S. Pat. No. 7,607,440), whichclaims benefit of Provisional Application No. 60/296,808 filed on Jun.7, 2001, the full disclosures of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention generally relates to methods and apparatus forenhancing surgical planning. More specifically, the invention relates tomethods and apparatus for planning, validating and simulating portplacement for minimally invasive surgery, such as laparoscopic and/orrobotic surgery.

Minimally invasive surgical techniques generally reduce the amount ofextraneous tissue damage during surgical procedures, thereby reducingpatient recovery time, discomfort, and deleterious side effects. Oneeffect of minimally invasive surgery, for example, is reducedpost-operative hospital recovery times. Because the average hospitalstay for a standard surgery is typically significantly longer than theaverage stay for an analogous minimally invasive surgery, increased useof minimally invasive techniques could save millions of dollars inhospital costs each year. Patient recovery times, patient discomfort,surgical side effects, and time away from work can also be reducedthrough the use of minimally invasive surgery.

In theory, a significant number of surgical procedures could beperformed by minimally invasive techniques to achieve the advantagesjust described. Only a small percentage of procedures currently useminimally invasive techniques, however, because certain methods,apparatus and systems are not currently available in a form forproviding minimally invasive surgery.

Traditional forms of minimally invasive surgery typically includeendoscopy, which is visual examination of a hollow space with a viewinginstrument called an endoscope. Minimally invasive surgery withendoscopy may be used in many different areas in the human body for manydifferent procedures, such as in laparoscopy, which is visualexamination and/or treatment of the abdominal cavity, or in minimallyinvasive heart surgery, such as coronary artery bypass grafting. Intraditional laparoscopic surgery, for example, a patient's abdominalcavity is insufflated with gas and cannula sleeves (or “entry ports”)are passed through small incisions in the musculature of the patient'sabdomen to provide entry ports through which laparoscopic surgicalinstruments can be passed in a sealed fashion. Such incisions aretypically about ½ inch (about 12 mm) in length.

Minimally invasive surgical instruments generally include an endoscopefor viewing the surgical field and working tools defining end effectors.Typical surgical end effectors include clamps, graspers, scissors,staplers, and needle holders, for example. The working tools are similarto those used in conventional (open) surgery, except that the workingend or end effector of each tool is separated from its handle by a longextension tube, typically of about 12 inches (about 300 mm) in length,for example, so as to permit the surgeon to introduce the end effectorto the surgical site and to control movement of the end effectorrelative to the surgical site from outside a patient's body.

To perform a minimally invasive surgical procedure, a surgeon typicallypasses the working tools or instruments through the entry ports to theinternal surgical site and manipulates the instruments from outside theabdomen by sliding them in and out through the entry ports, rotatingthem in the entry ports, levering (i.e., pivoting) the instrumentsagainst external structures of the patient and actuating the endeffectors on distal ends of the instruments from outside the patient.The instruments normally pivot around centers defined by the incisionswhich extend through the skin, muscles, etc. of the patient. The surgeontypically monitors the procedure by means of a television monitor whichdisplays an image of the surgical site captured by the endoscopiccamera. Generally, this type of endoscopic technique is employed in, forexample, arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy,cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, andthe like.

While traditional minimally invasive surgical instruments and techniqueslike those just described have proven highly effective, newer systemsmay provide even further advantages. For example, minimally invasiverobotic (or “telesurgical”) surgical systems have been developed toincrease surgical dexterity and allow a surgeon to operate on a patientin an intuitive manner. Telesurgery is a general term for surgicaloperations using systems where the surgeon uses some form of remotecontrol, such as a servomechanism or the like, to manipulate surgicalinstrument movements, rather than directly holding and mowing the toolsby hand. In such a telesurgery system, the surgeon is typically providedwith an image of the surgical site on a visual display at a locationremote from the patient. The surgeon can typically perform the surgicalprocedure at the location remote from the patient while viewing the endeffector movement on the visual display during the surgical procedure.While viewing typically a three-dimensional image of the surgical siteon the visual display, the surgeon performs the surgical procedures onthe patient by manipulating master control devices at the remotelocation, which master control devices control motion of the remotelycontrolled instruments.

Typically, a telesurgery system can be provided with at least two mastercontrol devices (one for each of the surgeon's hands), which arenormally operatively associated with two robotic arms on each of which asurgical instrument is mounted. Operative communication between mastercontrol devices and associated robotic arm and instrument assemblies istypically achieved through a control system. The control systemtypically includes at least one processor which relays input commandsfrom the master control devices to the associated robotic arm andinstrument assemblies and from the arm and instrument assemblies to theassociated master control devices in the case of, e.g., force feedback,or the like. One example of a robotic surgical system is the DAVINCI™system available from Intuitive Surgical, Inc. of Mountain View, Calif.

Improvements are still being made in laparoscopic, telesurgery, andother minimally invasive surgical systems and techniques. For example,choosing advantageous locations on a patient for placement of the entryports continues to be a concern. Many factors may contribute to adetermination of advantageous or optimal entry port locations. Factorssuch as patient anatomy, surgeon preferences, robot configurations, thesurgical procedure to be performed and/or the like may all contribute toa determination of ideal entry ports for an endoscope and surgicaltools. For example, ports should generally be placed in locations thatallow a surgical instrument to reach the target treatment site from theentry port. They should also be placed to avoid collision of two or morerobotic arms during a robotic procedure, or that allow free movement ofhuman arms during a laparoscopic procedure. Other factors such as anglesof approach to the treatment site, surgeon preferences for accessing thetreatment site, and the like may also be considered when determiningentry port placement.

If a robotic system is being used, robot positioning must also bedetermined, usually based at least in part on the port placement.Robotic placement will also typically depend on multiple factors, suchas robotic-arm collision avoidance, angles of entry for surgical tools,patient anatomy, and/or the like.

Currently available systems generally do not provide methods orapparatus for determining advantageous entry port placements forlaparoscopic, robotic, or other minimally invasive surgery. Althoughsome systems may designate locations for entry ports, they typically donot base those locations on a set of factors such as those justmentioned. Furthermore, currently available systems also do not providemethods or apparatus for validating whether given entry ports will befeasible or for simulating a surgical procedure using the chosen entryports.

Therefore, it would be advantageous to have methods and apparatus forplanning advantageous port placement for laparoscopic, robotic, andother minimally invasive surgery. Such methods and apparatus wouldideally also enhance planning of robot placement in robotic surgery. Itwould also be beneficial to have methods and apparatus which allowverification that a given set of entry ports will be feasible for agiven surgical procedure. Ideally, such methods and apparatus would alsoallow surgeons to simulate a surgical procedure using a set of entryports and to reject the entry ports if they proved unfeasible. Alsoideally, the methods and apparatus would be adaptable for non-surgicaluses, such as choosing port placement for robotic entry into non-humansystems for various purposes, such as for bomb defusion or handling ofhazardous materials.

BRIEF SUMMARY OF THE INVENTION

The present invention generally provides methods, apparatus and systemsfor enhancing surgical planning. More specifically, the inventionprovides methods, apparatus and systems which enhance the planning ofentry port locations, for entry of surgical tools into a defined volume,such as a body of a patient. The invention also generally provides forenhanced robot positioning in robotic surgery. Such planning isgenerally accomplished though a method of processing image data of apatient, selecting advantageous port placement based on the processeddata, selecting a robot position based on the port placement, andvalidating port placement and/or simulating an operation using theselected port and robot placements. Thus, embodiments of the presentinvention provide for more accurate, repeatable robotic operations whichrequire less manual planning from one operation to the next.

In one aspect, a method for identifying advantageous locations forplacement of two or more entry ports for performing an operation withina defined volume having a closed surface includes: preparing a model ofthe defined volume from a set of acquired data; defining at least onetarget area within the defined volume; and determining from the modeland the target area the advantageous locations for placement of the twoor more entry ports for performing the operation, the advantageouslocations being disposed on the closed surface of the defined volume.Optionally, the determining step may additionally include defining alist of possible locations for placement of each entry port andselecting an advantageous location for placement of each entry port fromthe list of possible locations for each entry port. In such embodiments,selecting the advantageous locations may be based at least in part on aset of criteria, the criteria including at least one of robotkinematics, robot kinetics, robot work range, deviation of tool entryangle from normal, organ geometry, surgeon defined constraints, robotforce limitations, and patient force limitations. In other embodiments,selecting the advantageous location for placement of each entry port isbased at least in part on a cost function, the cost function at leastpartially defined by at least one of minimizing deviations from adesired configuration, arm placement symmetry with respect to endoscopepositioning, and minimization of tool entry angle with respect tosurface normal.

In some embodiments, the operation comprises a surgical operation on abody of a patient and the defined volume comprises a volume of at leasta portion of the body. In other embodiments, the operation comprises anoperation on a munitions material, the operation including at least oneof inspection, maintenance, disabling, and mechanical interaction.Typically, the acquired data comprises imaging data acquired using atleast one of computed tomography and magnetic resonance imaging, thoughother modalities may be used.

As mentioned briefly above, some embodiments include determining aposition for placement of a robot relative to the defined volume forperforming the operation. In such embodiments, determining the positionof the robot may be based at least in part on a set of criteria, thecriteria including at least one of robot kinematics, robot kinetics,robot work range, deviation of tool entry angle from normal, organgeometry, surgeon defined constraints, robot force limitations, andpatient force limitations.

As also mentioned above, some embodiments include providing a firstsimulation for enabling a user to simulate the operation, the firstsimulation based upon the model of the defined volume, the target area,and the advantageous locations of the entry ports. Where a simulation isprovided, some embodiments will also enable the user to reject one ormore of the advantageous locations based on the first simulation,determine different advantageous locations based on the user'srejection, and provide a second simulation for enabling the user tosimulate the operation, the second simulation being based upon the modelof the defined volume, the target area, and the different advantageouslocations of the entry ports.

In another aspect, a method for identifying advantageous locations forplacement of two or more entry ports for performing a surgical operationon a body of a patient includes preparing a model of at least a portionof the patient's body from a set of acquired data, using the model todefine at least one target area within the body, defining a list ofpossible locations for each of the two or more entry ports, the possiblelocations being disposed on a surface of the body, and selecting anadvantageous location for placement of each of the two or more entryports from each list of possible locations.

In yet another aspect, a method for identifying advantageous locationsfor placement of two or more entry ports for performing a surgicalprocedure on a body of a patient includes defining a list of possiblelocations for each of the two or more entry ports, the possiblelocations being disposed on a surface of the body, selecting, based on aset of criteria, an advantageous location for placement of each of thetwo or more entry ports from each list of possible locations, verifyingthat the selected location for placement of each entry port is feasible,and providing means for simulating the surgical procedure. In someembodiments, the set of criteria includes at least two of robotkinematics, robot kinetics, robot work range, deviation of tool entryangle from normal, organ geometry, surgeon defined constraints, robotforce limitations, and patient force limitations. In other embodiments,the set of criteria includes a cost function, the cost function at leastpartially defined by at least one of minimizing deviations from adesired configuration, arm placement symmetry with respect to endoscopepositioning, and minimization of tool entry angle with respect tosurface normal.

In another aspect, an apparatus for identifying advantageous locationsfor placement of two or more entry ports for performing an operationwithin a defined volume having a closed surface includes a computersoftware module for identifying the advantageous locations, and acomputerized simulation device for simulating the operation using thecomputer software and the advantageous locations.

In yet another aspect, a system for performing a robotic operationwithin a defined volume having a closed surface includes a robot havingat least two robotic arms, a computer coupled with the robot for atleast partially controlling movements of the robotic arms, and computersoftware couplable with the computer for planning advantageous locationsfor at least two entry ports into the defined volume by the at least tworobotic arms and for providing a simulation of the robotic operation.Optionally, the robot may include at least two robotic arms forattaching surgical tools and at least one robotic arm for attaching animaging device. Also optionally, the computer may include a displaydevice for displaying the simulation of the robotic operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overhead view of a robotic surgical system for use in anembodiment of the present invention.

FIG. 2 is a perspective view of a master control workstation and apatient-side cart having three robotic manipulator arms for use in thesystem of FIG. 1.

FIG. 3 is a flow diagram of a method for enhancing port placement inrobotic operations according to an embodiment of the present invention.

FIG. 4 is a flow diagram of the preliminary data processing stage of amethod as in FIG. 3 according to an embodiment of the present invention.

FIG. 5 is a line diagram showing various angles between an entry portlocation and a target according to an embodiment of the presentinvention.

FIG. 6 is a diagram of an internal collision detection logic used in anembodiment of the sent invention.

FIG. 7a is a side view of an experimental validation of the results of asurgical procedure using methods and apparatus of an embodiment of thepresent invention.

FIG. 7b is a close-up perspective view of the validation in FIG. 7 a.

FIG. 7c is a side view of a computer validation of a surgical procedureas shown in FIG. 7 a.

FIG. 7d is a perspective view of a computer validation of a surgicalprocedure as shown in FIG. 7 b.

FIG. 8a is a screen shot side view of a computer interface forsimulation of a surgical procedure according to an embodiment of thepresent invention.

FIG. 8b is a screen shot perspective view of a computer interface forsimulation of a surgical procedure according to an embodiment of thepresent invention.

DETAILED DESCRIPTION

The present invention generally provides methods and apparatus forenhancing planning of laparoscopic, robotic, and other minimallyinvasive surgery. More specifically, various embodiments provide methodsand apparatus for planning advantageous locations for placement of twoor more entry ports for accessing a defined volume, such as a patient,with surgical tools to perform a minimally invasive operation. Inrobotic surgery, robot position will typically also be planned.Additionally, many embodiments provide validation that selected entryport placements and/or robot positions will be feasible for a givenoperation. Many embodiments also provide simulation of a givenoperation, using selected entry port placements and/or robot positions,to allow a surgeon or other user to practice using the surgical system.

Although the following description focuses on planning port placementand robot position in a robotic surgery context, specifically in a heartsurgery context, many other applications are contemplated within thescope of the invention. As mentioned above, for example, variousembodiments may be used in other surgical contexts, such as non-roboticlaparoscopic/abdominal surgery, arthroscopy, retroperitoneoscopy,pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy,hysteroscopy, urethroscopy, and the like. Furthermore, non-surgicalapplications are contemplated, including but not limited to handling,disabling, maintaining and/or the like of munitions, hazardousmaterials, and/or other suitable materials. Within the surgical context,methods and apparatus of the present invention may be used with manydifferent systems for conducting robotic or minimally invasive surgery.One example of a robotic surgical system which may incorporate methodsand apparatus of the present invention is the DAVINCI™ system availablefrom Intuitive Surgical, Inc. of Mountain View, Calif. Many othersurgical systems and apparatus may be used, however. Therefore, thefollowing description is provided for exemplary purposes only and shouldnot limit the scope of the present invention as set forth in theappended claims.

Referring now to FIG. 1, one example of a robotic surgical system 10,with which the methods and apparatus of the present invention may beused, includes a master control station 200 and a slave cart 300.Optionally, any of several other additional components may be includedin the surgical system to enhance the capabilities of the roboticdevices to perform complex surgical procedures. An operator O performs aminimally invasive surgical procedure at an internal surgical sitewithin patient P using minimally invasive surgical instruments 100.Operator O works at master control station 200. Operator O views adisplay provided by the workstation and manipulates left and right inputdevices. The telesurgical system moves surgical instruments mounted onrobotic arms of slave cart 300 in response to movement of the inputdevices. As described in co-pending U.S. patent application Ser. No.09/436,527, filed on Dec. 14, 2001 (Attorney Docket No. 17516-002530),the full disclosure of which is incorporated herein by reference, aselectively designated “left” instrument is associated with the leftinput device in the left hand of operator O and a selectively designated“right” instrument is associated with the right input device in theright hand of the operator.

As described in more detail in co-pending U.S. patent application Ser.No. 09/373,678 entitled “Camera Reference Control in a MinimallyInvasive Surgical Apparatus,” filed Aug. 13, 1999 (the full disclosureof which is incorporated herein by reference) a processor of mastercontroller 200 will preferably coordinate movement of the input deviceswith the movement of their associated instruments, so that the images ofthe surgical tools, as displayed to the operator O, appear substantiallyconnected to the input devices in the hand of the operator.

Optionally, an auxiliary cart A can support one or more additionalsurgical tools 100 for use during the procedure. One tool is shown herefor the illustrative purposes only. A first assistant A1 is seated at anassistant control station 200A, the first assistant typically directingmovement of one or more surgical instruments not actively beingmanipulated by operator O via master control station 200, such as atissue stabilizer. A second assistant A2 may be disposed adjacentpatient P to assist in swapping instruments 100 during the surgicalprocedure. Auxiliary cart A may also include one or more assistant inputdevices 12 (shown here as a simple joystick) to allow second assistantA2 to selectively manipulate one or more surgical instruments whileviewing the internal surgical site via an assistant display 14.Preferably, the first assistant A1 seated at console 200A has the sameimage as the surgeon seated at console 200.

Master control station 200, assistant controller 200A, cart 300,auxiliary cart 300A, and assistant display 14 (or subsets of thesecomponents) may allow complex surgeries to be performed by selectivelyhanding off control of one or more robotic arms between operator O andone or more assistants. Alternatively, operator O may actively controltwo surgical tools while a third remains at a fixed position. Forexample, to stabilize and/or retract tissues, with the operatorselectively operating the retracting or stabilizer only at designatedtimes. In still further alternatives, a surgeon and an assistant cancooperate to conduct an operation without either passing control ofinstruments or being able to pass control of instruments with bothinstead manipulating his or her own instruments during the surgery.

Although FIG. 1 depicts two surgeon consoles controlling the two cartstructures, a preferred embodiment comprises only one consolecontrolling four or more arms on two carts. The scope may optionally bemounted on the auxiliary cart, and three tissue manipulator arms may bemounted on the main cart. In some embodiments, one or more tools,particularly tissue stabilizers, may not be actively driven, insteadbeing positioned by manually actuating a drive system of the tool andthen locking the tool into position.

Referring now to FIG. 2, master control station 200 includes a viewer202 wherein an image of a surgical site is displayed in use. A support204 is provided on which the operator, typically a surgeon, can rest hisor her forearms while gripping two master controls, one in each hand.Master controls are positioned in a workspace 206 disposed inwardlybeyond support 204. When using workstation 100, the surgeon typicallysits in a chair in front of the workstation, positions his or her eyesin front of the viewer 202 and grips the master controls.

FIG. 2 shows also the surgical manipulator slave or cart 300 of thetelesurgical system. In use, cart 300 is positioned close to a patientfor surgery, and the base of the cart is caused to remain stationaryuntil the surgical procedure, has been completed. Cart 300 here includesthree robotic manipulator arm assemblies 302, each manipulatorsupporting an instrument 100. More specifically, one of the robotic armassemblies supports an image capture device, such as an endoscope 306(which is coupled to display 102 of the workstation). Each of the othertwo manipulator arms supports a tissue manipulation tool 308 having asurgical end effector for treating tissue.

Finally, FIG. 2 shows a processor 400 coupled with master controlstation 200 and cart 300 and a tangible medium 410 embodying machinereadable code, or software. The software typically includes instructionswhich enable various embodiments of the methods of the presentinvention. The tangible medium 410 may be coupled with the processor 400for use. Generally, the software may be used with any suitable hardware,such as a personal computer work station with graphics capabilities,such as but not limited to a PENTIUM III® or equivalent processor with aGEFORCE2® graphics card. Other hardware which may be used with softwareof the present invention includes a display monitor, such as a 17″monitor, a processor with 256 Mbytes of RAM and a 10 Gigabytes harddisk. Input devices will typically include a mouse and may also includea 3D mouse or a PHANTOM® arm.

Although in some embodiments, as just described, hardware will include astand-alone PC workstation or similar stand-along hardware, otherembodiments will be integrated with an existing system. For example,hardware may be embedded in a dedicated apparatus such as a roboticsurgical system. In one embodiment, hardware is embedded in a part ofDAVINCI® robotic system (Intuitive Surgical, Inc., Sunnyvale, Calif.)such as the master control station 200.

The robotic manipulator arms will move and articulate the surgical toolsin response to motions of the input devices at the workstation, so thatthe surgeon can direct surgical procedures at internal surgical sitesthrough minimally invasive surgical apertures. The workstation 200 istypically used within an operating room with the cart, but can bepositioned remote from the cart, even miles away. An exemplary mastercontrol input device for manipulation by the surgeon is more fullydescribed in co-pending U.S. patent application Ser. No. 09/398,507,entitled “Master Having Redundant Degrees of Freedom,” as filed on Sep.17, 1999, the full disclosure of which is incorporated herein byreference. Exemplary manipulator arms are more fully described inco-pending U.S. patent application Ser. No. 09/368,309 as filed on Aug.3, 1999, for a “Manipulator Positioning Linkage for Robotic Surgery,”(the full disclosure of which is also incorporated herein by reference),which also describes manually positionable linkages supporting themanipulators. It should be noted that a number of alternative roboticmanipulator arms might be used, including those described in U.S. Pat.No. 5,855,583, the full disclosure of which is also incorporated hereinby reference.

Referring now to FIG. 3, a method for enhancing port placement 12suitably includes four general steps or stages. In various alternativeembodiments, certain steps may be combined, other steps may be added,and/or one or more steps may be eliminated, without significantlychanging the overall result. That being said, four general stages usedto plan entry port placement may include preliminary data processing110, planning 120, validation 130 and simulation 140.

Preliminary data processing 110 generally includes processing imagingdata, such as radiological data from computed tomography (CT) and/ormagnetic resonance imaging (MRI) scans. Such processing may includesegmentation, 3D reconstruction, robot modeling and/or the like.Planning 120 generally includes choosing locations for two or more entryports into a defined volumetric space, such as a patient, for allowingentry of surgical tools, robotic tools or arms, one or more endoscopes,retractors, and/or the like. Typically, planning 120 involves combiningdata in an optimization algorithm where mathematical criteria have beenintegrated. The criteria translate features such as collision avoidancebetween the manipulator arms and reachability of targeted organs.Validation 130 refers to a process of testing the feasibility of theoperation by reproducing the expected movements of the surgeon andlooking for collisions or other problems, such as an out of reachcondition. Finally, simulation 140 allows a surgeon or other user to usethe chosen entry ports and robot position to perform a practiceoperation. In many embodiments, if the surgeon judges the proposed portsand/or robot position less than optimal, the surgeon may reject thechosen locations and new ones may be chosen by the system.

Each of the steps or processes described above may involve variouscomponents or steps in various embodiments. For a more detaileddiscussion of each step, see the master's thesis of Louai Adhami,attached as Exhibit C to U.S. Provisional Patent Application Ser. No.60/296,808, previously incorporated by reference. For example, withreference to FIG. 4, some embodiments include multiple stages or stepsat the preliminary data acquisition 110 phase. In one embodiment, forexample, steps include data acquisition 112, segmentation 114,reconstruction 116 and robot modeling 118. Again, in various embodimentsthese steps may be carried out in any suitable order and/or steps may beadded, eliminated, and/or carried out simultaneously.

Data acquisition 112 generally involves acquiring any data regarding avolume which is to be operated upon, such as a portion of a patient'sbody, as well as, in some embodiments, data regarding a robot, surgicaltools, and the like, to be used in performing the operation. Data mayinclude, for example, CT scan data, with or without contrast, MRI data,coronary artery angiograms, conventional radiographs, digitalrepresentations of conventional radiographs, and/or the like. In atotally endoscopic coronary artery bypass graft (TECAB) operation, forexample, CT scan data is typically used. This generally involvesacquiring helical CT scans of a patient, with 3 mm spacing, fromapproximately the neck region to the hip region of the patient. Slicesize is often decreased to 1 cm in the area of the heart, to acquiremore image information, and often a dye is injected to better visualizethe heart and aorta. Additionally, such CT data acquisition will oftenbe synchronized with electrocardiogram (ECG) data acquisition. Coronaryangiograms may also be acquired, to enable an accurate diagnosis of thestate of heart vessels. Data from multiple types of imaging studies,such as CT scans and angiograms, may be used together in variousembodiments to enhance planning of port placement.

Segmentation 114 generally first involves separating out differentanatomical entities within the defined volume of the operation, such asvarious anatomical organs and tissues within a patient. For a TECABprocedure, for example, bones (such as ribs), heart, and left inferiormammary artery (LIMA) are typically segmented. Segmentation of bonesfrom surrounding soft tissues is automatically performed, based on thesignificantly higher density of the bones, by the “extractcontour”computer software. (“Extractcontour” is software developed by INRIASophia Antipolis, and is in the public domain and available from INRIA.)Heart and LIMA segmentation are generally performed manually, such as bya radiologist or other suitable technician. The LIMA is approximated bya fixed-size circle on each CT slice, in an area specified manually. Theheart is approximated by splines built around a set of points that aremanually drawn. Typically, this process is invariant from one patient toanother, meaning that it does not require adjustments by a radiologistor other radiology technician between patients.

Another part of the segmentation step 114 is to define admissible pointsfor entry into the defined volume, as well as admissible directions forentry. In other words a list is compiled of possible entry points anddirections. Admissible points of entry are sites on a surface of thevolume that allow the introduction of robot arms, an endoscope, and/orany other tools to be used for the operation. In a TECAB operation, forexample, admissible points may include any points within the intercostalspaces (spaces between the ribs) of a patient. Points which would causea tool to pass through bone, such as a rib, are typically eliminated asnot being admissible. Admissible directions are directions generallypointing outward and perpendicular to the skin, which replicatedirections of orientation that robotic arms, endoscopes and the likewill have during the operation.

Another component in preliminary data processing 110 is reconstruction116. Reconstruction 116 generally refers to formation of acquired,segmented data into a 3-dimensional model of the defined volume whichwill be operated upon. Generally, such 3D models are constructed usingcomputer software, such as the nuages software, described in Bernhard.Geiger, “Three Dimensional Modeling of Human Organs and its Applicationto Diagnosis and Surgical Planning,” Technical Report 2105,INRIA-Sophia, 1993, the entire contents of which is hereby incorporatedby reference. A public version of nuages software is available atftp://Hftp-sop.inria.fr/prisme/NUAGES/Nuages. Again, this software maybe run on conventional, off-the-shelf hardware, such as a PENTIUM III®processor. The underlying algorithm used for reconstruction 116 viaimages software is based on projected Vorono diagrams, where the inputis a set of closed non-intersecting contours, and the output is a meshof triangles representing the reconstructed surface in 3D. Thisalgorithm has the advantages of outputting a relatively low, manageablenumber of triangles and of not being prone to distortive effects such asthe staircase effect observed in marching cubes algorithms.

Another aspect of preliminary data processing 110, in some embodiments,includes robot modeling 118. Generally, robot modeling 118 involvescombining a geometric model of a robot with the acquired radiologicaldata from the patient or other defined volume in an interactiveinterface. In the preliminary phase, for example, Denavit-Hartenberg(DH) models may be used, along with a generic C++ library, where OPENGL™output and collision detection are implemented. In one embodiment twoprimitives are retained for the modeling of the robot body, namelyrectangular parallelepipeds and cylinders. Part of robot modeling 118typically includes using inverse kinematics, either analytically ornumerically, to detect possible interferences between links of therobot. In other words, collision detection is carried out. Forefficiency purposes, a dedicated interference detection method mayinclude a hierarchical method based on direct collision tests betweenthe different modeling primitives (cylinders and rectangularparallelepipeds), in addition to spheres. This method can be extendedaccordingly if the model is refined, with more complex primitives. Ananalytic solution is used when there is the same number of degrees offreedom (dofs) and constraints, whereas a numerical solution is usedwhen there are more dofs than constraints. In the latter case,artificial constraints are added to reflect the proximity between thearms, which would be of great significance when dealing with the problemof collision avoidance.

With reference again to FIG. 3, after preliminary data processing 110planning 120 is performed. Planning 120 generally consists ofidentifying advantageous locations for two or more entry ports foraccessing the defined volume to be operated upon. In many embodiments,planning 120 also includes planning one or more positions of a robotand/or its component parts for performing an operation, with the robotpositioning being based on the advantageous locations of the two or moreentry points. Typically, planning 120 is carried out to identify optimalor advantageous entry port locations for three tools, such as two robotarms and an endoscope. Multiple criteria are generally used to helpidentify such locations, and the locations are selected from among theadmissible entry points described above. Thus, one embodiment involveschoosing a “triplet” of three entry points that optimizes a set ofpredefined criteria. The criteria may be any suitable criteria, such asrobot constraints, anatomical constraints, surgeon preferences, and/orthe like.

In one embodiment, for example, some criteria are derived from surgeonpreferences, For example, a surgeon may specify target points within thepatient or other defined volume on which the surgeon wants to operate,such as points on or in a heart in heart surgery. Target points may thenbe used to define a target area, within which the surgeon wishes tooperate. The surgeon also typically defines one or more preferred“attack directions,” which are generally directions from which thesurgeon prefers to access the target points. “Attack angles” may bederived from these attack directions. An attack angle is an anglebetween the attack direction at the target point on the one hand, andthe straight line connecting the latter to an admissible point (on asurface of the patient) on the other. It reflects the ease with whichthe surgeon can operate on a given location with respect to the attackdirection chosen by the surgeon. A “dexterity parameter” is anothercriteria which may be used. The dexterity parameter is proportional tothe angle between the surface normal at the admissible point and astraight line connecting the latter to the target point. This measure ofdexterity is typically interpreted in accordance with the robotcapabilities.

Other criteria which may be used in identifying advantageous locationsfor entry ports include both qualitative and quantitative criteria.Referring now to FIG. 5, qualitative criteria, for example, may relateto the reachability from an admissible point 210 to a target point 212,with the admissible point being eliminated from consideration if a toolto be used in the operation is not long enough to reach across distance214 to reach target point 212.

In another criteria, an admissible point may be eliminated if an angle222 between a surface of the patient at the entry point and a line fromthe entry point to the target point 212 is too large, such that use of atool through that entry point may cause damage to a nearby structure.Use of such an entry point in a heart operation, for example, may causedamage to a rib. Yet another criteria which might be used to eliminatean admissible point would be if the combination of the admissible entrypoint, surgical tool, attack direction and target point would result inthe tool passing through an anatomic structure. For example, if the toolwould pass through a lung on its way to the heart, that admissible pointwould be eliminated. Computer graphics hardware may be used to performthis test in a method similar to that described in “Real-time CollisionDetection for Virtual Surgery,” by J.-C. Lombardo, M. P. Cani and F.Neyret, Computer Animation, Geneva, May 1999, the entire contents ofwhich is hereby incorporated by reference.

Quantitative criteria generally relate to dexterity of the robot, whereeach admissible point is graded based on an angle 212 between the attackdirection and the line relating target point 212 to admissible point210. This measure translates the ease with which the surgeon will beable to operate on target areas from a given port in the case of arobotic tool, or the quality of viewing those areas via an endoscope.

Criteria such as those described above may be applied in various ordersand by various means. In one embodiment, for example, identifying anadvantageous triplet of entry port locations is accomplished in twobasic steps: First an entry port for an endoscope is chosen based onvarious criteria, then admissible entry port locations for two (oranother number) tools are ranked according to their combinedquantitative grade and their position with respect to the endoscope.More precisely, the triplet (of endoscope port and two tool ports) isranked to provide a desirable symmetry between two robot arms and theendoscope, and to favor positions of the robot arms at maximum distancesfrom the endoscope to provide the surgeon with a clear field of view.

Applying criteria in this way may involve several steps. For example, inone embodiment a first step involves eliminating admissible entry portlocation candidates that will not provide access to the target areas. Ina next step, admissible sites for an endoscope are sorted to minimizethe angle between the target normal and the line connecting theadmissible point to the target point. This step gives precedence toentry ports for the endoscope that provide a direct view over the targetareas and, therefore, ports which would create angles greater than adesired camera angle are eliminated. In applying such criteria, targetsareas may be weighted according to their relative sizes. For robot arms,admissible entry points may be sorted in the same way as for theendoscope, but with the angle limitation relaxed. Admissible candidatesthat make too obtuse an angle between the tool and the skin may beeliminated. For example, an maximum angle of 60.degree. may be chosen ina heart operation to avoid excessive stress on the ribs. Finally, atriplet combination of three entry ports (or however many entry portsare to by used) may be chosen to optimize the criteria discussed abovewhile also maximizing the distances between the ports. This distancemaximization criteria will prevent collision between robot arms andallow the surgeon to operate the robotic arms with a relatively widerange of movement.

Once a set of advantageous entry port locations has been selected, anadvantageous position for placement of the robot to be used, in relationto the patient, is typically determined. Robot positioning willtypically be based on the entry port placement and the robotconfiguration, such that the robot is positioned in a way that avoidscollisions between robot arms and allows the arms to function inperforming a given operation without violating any of a number ofselected constraints. Constraints may include, for example, number ofrobot arms and number of degrees of freedom for each arm, potentialcollisions between the robot arms, potential collisions between an armand the patient, other potential collisions (e.g. with anesthesiaequipment or operating room table), and/or miscellaneous constraints(e.g. endoscope orientation for assistant surgeon). Certain constraintsmay be more subjective, such as surgeon preferences, operating roomconfigurations and the like.

To determine an advantageous robot position, one method uses a combinedprobabilistic and gradient descent approach, where configurations of thepassive joints (including a translation of the base) are randomly drawnin robot articular space. To each configuration, a cost function isassociated that depends on the constraints discussed above. A low costfunction gives its corresponding robot configuration a high selectionprobability. This process is repeated until a configuration arrives at acost function that is less than a given threshold. Once the costfunction is low enough (i.e., the passive joints are close enough to thedesired port), the active joints are moved over all the targets (usinginverse kinematics), to verify that there are no collisions.

Returning to FIG. 3, once a suitable triplet or other configuration ofentry port locations has been identified, validation 130 is performed toverify that the identified locations are feasible for carrying out thegiven operation. In most embodiments, the robot is placed in theposition which has been selected and movement of the robot as will bedone during the operation is carried out to took for possible collisionsbetween the robot arms. Generally, the trajectory between two targetareas is a straight line, and this is the way a surgeon is expected tonavigate. The possibility of collisions between discrete time steps ishandled by an interference detection algorithm that tests sweeps thevolume covered by the manipulator arms. In addition to interferencedetection, out of reach conditions and possible singularities aremonitored and signaled. Finally, the endoscope is positioned relative tothe tips of the tool arms at a predefined distance, in a way toguarantee a good visibility at all times. If no problem is detectedduring validation 130, then the triplet or other configuration isaccepted and a surgeon may proceed with simulation 140. If there is acollision or other problem, the system may return to the planning stage120 to select other entry port locations.

Simulation 140 generally provides a surgeon or other operator of arobotic system an environment in which to practice a given operation todevelop facility with the robot and to re-validate the selected,advantageous entry port locations. Generally, simulation 140 is carriedout using robotic control mechanisms, a computer with a monitor, andcomputer software to enable the simulation. Thus, the validation 130step just described and the simulation step 140 are typically carriedout using computerized systems. Using simulation 140, a surgeon canessentially perform the operation as it would be performed on a livepatient, as simulated on a 3-dimensional representation on a computermonitor, to practice use of the robotic system and to confirm that theselected combination of robot position and entry port locations isfeasible.

As with the validation step 130, simulation 140 typically includescollision detection for possible collisions between the robot arras.Collisions are typically stratified as internal (between themanipulators) and external (with the anatomical entities). Internalcollisions may be further divided into static and dynamic (continuousmovement) collisions. In most embodiments, an algorithm is used todetect possible internal collisions, the algorithm detectinginterferences between rectangular parallelepipeds and cylinders. FIG. 6,for example, shows a diagram of an internal collision detection logicwhich may be used. In that logic, testing for an intersection betweentwo boxes is accomplished by looking for an overlap between one of theboxes and the sides of the other. The same can be done for two cylindersor between a box and a cylinder. For further details regarding thisalgorithm, see master's thesis of Louai Adhami, attached as Exhibit C toU.S. Provisional Patent Application Ser. No. 60/296,808, which haspreviously been incorporated by reference. (Also see doctoral thesis ofLouai Adhami, available from INRIA Sophia after Jul. 3, 2002.)

External collisions, on the other hand, are typically detected usinggraphics hardware and a method such as that suggested in “Real-timeCollision Detection for Virtual Surgery,” by J.-C. Lombardo, M. P. Caniand F. Neyret, Computer Animation, Geneva, May 1999, previouslyincorporated herein by reference. Sufficient graphics hardware mayinclude, for example, a personal computer work station with graphicscapabilities, such as a PENTIUM III® or equivalent processor with aGEFORCE2® graphics card, and any suitable monitor.

Referring now to FIGS. 7a -d, a system for planning, validating, andsimulating port placement may first be calibrated, or experimentallyadjusted, using a physical, structural modeling system. For example,FIGS. 7a and 7b show an experimental validation of port placement androbot position for a TECAB procedure using a skeleton rib cage. FIGS. 7cand 7d show a computerized representation of the same experimentalvalidation. Such physical validation on a skeleton, cadaver, or otherstructural model will not be necessary in typical use of the methods andapparatus of the present invention. Generally, validation 130 andsimulation 140 steps will be carried out using the robotic system and acomputerized system, and will not involve physical, structural models.If use of such models were found to be advantageous for general use ofvarious embodiments, however, such models are within the scope of thepresent invention.

FIGS. 8a and 8b show screen shots representing an embodiment of anapparatus for simulation 140 of a surgical procedure. FIG. 8a is ascreen shot side view of a computer interface for simulation of a TECABprocedure. The interface may allow a surgeon to manipulate thecomputerized view of the simulation, to view the simulation from otherangles, for example. FIG. 8b is a similar screen shot perspective viewof a computer interface for simulation of a TECAB procedure.

Again referring to FIG. 3, once entry port placement and robotpositioning have been validated 130 and simulated 140, they may beregistered 150. Registration 150 generally refers to a process oftransferring the entry port and robot placement from a simulator to anactual defined volume, such as a patient in an operating room (“OR”). Inone embodiment, it is assumed that the robot base will be parallel tothe OR table, and that the relative tilt between the skeleton used forsimulation (or other simulation device) and the OR table is the same asthe one in the CT scan. The translational pose is registered byidentifying an particular point (such as the tip of the sternum) in thesimulator using the endoscope, and reading the corresponding articularvalues. Then the robot base and its first translational joint (up/down)are moved so that the articular values read through an applicationsprogram interface (API) match the computed ones. Generally, an API is aninterface including data from robot arm sensors, various other robotsensors, and the like, for registering robot positioning.

Once the robot is registered to the simulation skeleton, positioning theports may simply be achieved by moving the robot arms according to theprecomputed articular values that correspond to having the remote centeron the port. On the other hand, the results of the planning can also beexpressed as a quantitative description of the positions of the port,for example endoscope arm at third intercostal space at the limit of thecartilage. This is a relatively accurate description since the ports areplanned to be located in the intercostal spacing. When entry portlocations are identified and the robot is positioned, a surgeon or otheroperator may begin the procedure.

As described above, one embodiment of the present invention may bedescribed as a method for surgical planning. The following is a moredetailed description, set forth in a series of steps, of such anembodiment. Again, this description is provided for exemplary purposesonly. In other embodiments, multiple steps may be added, eliminated,combined, performed in different orders, performed simultaneously,and/or the like, without departing from the scope of the invention.Therefore, the following description should not be interpreted to limitthe scope of the invention as defined by the appended claims.

EXAMPLE METHO

Step 1: Robotic system modeling. Step 1 typically includes defining amodel of the insertable surgical tool portion, including structure,range of motion (ROM) limits, and optionally tool-type specificproperties. Step 1 also includes defining a model of the externalportion or robotic tool and manipulator arm structure and ROM limits.Finally, step 1 includes defining a multiple-arm robotic system model.Optionally, the model may include adjacent OR equipment such asoperating table and accessories.

Step 2: Defining port feasibility criteria. Port feasibility may bedefined, for example, relative to “teachability” criteria based onpatient and tool models. Such criteria may include, for example: maximumacceptable port-to-target distance (i.e., tool shaft length, forendoscope, may include an objective lens offset); maximum acceptableentry angle, the angle between port-to-target path and the portdirection—may depend on body wall properties, intercostal spacing,thickness, elasticity, etc., and may have different values in differentbody regions; determination that port-to-target path is clear ofobstructions; and/or additional feasibility criteria (e.g., surgeonpreference, procedure specific or tool-type specific criteria).

Step 3: Defining port optimization criteria. Examples of criteriainclude: tool-to-target attack angle for each port; dexterity parameter;tool 1 to endoscope angle; tool 2 to endoscope angle; symmetry andalignment of Tool 1 and Tool 2 about Endoscope; port-to-port separationdistance; and/or additional optimization criteria (e.g., surgeonpreference, procedure specific or tool-type specific criteria).

Step 4: Defining port optimization algorithm. For example, a costfunction may be defined, wherein the function value is determined byweighted criteria values.

Step 5; Defining collision/interference prediction algorithms. Step 5involves, for example, defining collision and interferenceprediction/detection algorithms relative to robotic system and/orpatient models. Examples of such algorithms may include: internaltool-tool and/or tool-organ collisions; external arm-arm, arm-equipmentand/or arm-patient collisions.

Step 6: Defining operative motion prediction algorithms. This stepinvolves defining a predictive model of expected range ofsurgeon-commanded operational tool movements during surgical task(generic task, specific procedural and/or tool-types).

Step 7: Modeling the patient. Various exemplary embodiments include theuse of patient-specific data to characterize the body portion beingtreated. In some embodiments and surgical procedures, port optimizationplanning on a representative sample of patients will have sufficientgenerality to be useful as a generic port placement plan. Modeling apatient may involve several sub-steps, such as:

1. acquiring patient-specific data for at least a portion of patent'sbody via such modalities as CT, MRI, and or arterial angiograms;

2. segmenting acquired data to distinguish organ, bone, vessel and othertissue structures (may be automated, manual or a combination of these);

3. reconstructing segmented, acquired data to construct a 3D model forat least a portion of patent's body. Optionally, such a model mayinclude additional overlaid patient data, a body cavity insufflationspace model, and/or the like.

Step 8: Defining target criteria. Step 8 includes defining one or moresurgical target points (e.g., location in the body of a particularintended tissue manipulation) and target direction(s) in relation topatient model, (the direction(s) most convenient for performing thesurgical task, e.g., normal to an organ surface or a preferred directionrelative to an organ structure). Target directions may be different forendoscope and each tool. A process model of the interventional surgicalprocedure may be defined, specifying one or more relevant surgicaltargets.

Step 9: Defining admissible port set. This step involves defining a setof admissible ports for target and/or surgical procedure in relation topatient model, includes the entry point location and normal directionfor each port. The choice of the admissible locations set stems from thecharacteristics of the intervention and/or anatomy of the patient, andis meant to cover all possible entry points from which optimal ports areto be chosen. Determining this set can either be done empirically orautomatically using specialized segmentation algorithms.

Step 10: Determining feasible port set. This step includes calculatingport feasibility criteria for each admissible port, testing portfeasibility, and eliminating failed ports.

Step 11: Determining optimized multiple-port combination. Step 11 mayinclude applying an optimization algorithm to calculated optimizationcriteria for all feasible port combinations of the total arm number(e.g., all feasible 3-port combinations or triplets). Step 11 may alsoinclude adding more ports than arms for surgeon assistance (e.g. cardiacstabilizer). The total number of ports is often referred to as n-tuplet.Several ports may be chosen for the same arm (e.g. two differentnon-simultaneous positions of the endoscope). Alternatively, step 11 mayinclude pre-selecting an endoscope port, and then optimizing other portsby considering all combinations of remaining feasible ports (in examplebelow, remaining feasible port pairs), as in the following sub-steps:

1. optimizing endoscope port, e.g., selecting port for port-to-targetpath close to target direction;

2. optional port pair feasibility criteria, e.g., eliminating part pairswith less than a minimum port surface separation, to simplifyoptimization by avoiding highly probable internal and externalcollisions, and/or aberrant ports with regard to dexterity and/orvisibility; and

3. optimizing tool(s) and/or endoscope(s) combinations. For 1endoscope+2 tools, each combination is commonly referred to as atriplet. More generally, for 1 endoscope+n-1 tools, each combination isreferred to as an n-tuplet. Note that the combination may include morethan one endoscope, or an integrated multifunctional endoscope/tool.This step may include, for example, calculating the optimizationcriteria for each port combination; calculating cost function value;ranking the n-tuplet by cost function value; and selecting the n-tupletwhich has the best cost function value.

Step 12: Determining an advantageous robotic system pre-surgical set-upconfiguration. Although the robotic system pre-surgical set-upposition(s) may be determined empirically, preferably optimizationmethods are employed according to the principals of the invention. Thismay include determining positions for a portion or all of the “passive”flexibility degrees of freedom (dofs) of the system (i.e., “passive” inthe sense of fixed during surgical treatment manipulation), includingthe base support position(s), base support orientation(s), set-up jointposition(s), and the like. Note that different robotic surgical systemsvary considerably in the number of passive pre-surgical set-up dofs. Anexemplary process (e.g., probabilistic and gradient descent) mayinclude:

1. defining a set of constraints on the system based on port locationand/or trajectory modeling the intervention;

2. defining a cost function based on a measure of goodness including,e.g., separation between the arms; separation from obstacles; maximizingdexterity and/or maneuverability at the end effector(s);

3. running probabilistic optimization to get a set of admissible(constraints realized) solutions (position/orientation of the baseand/or values for set-up joints); and/or

4. running gradient descent optimization from the above initialsolutions to optimize measure of goodness.

Step 13: Performing validation. The validation step involves applyingthe predictive model of expected surgeon-commanded operationalinstrument movements for a surgical procedure during manipulations at asurgical target site within the body. (e.g., the range of motions ofinstrument end effector, wrist and shaft within the body cavity relativeto the body model; the range of motions of robotic arms outside the bodyrelative to system model and/or body model). Collision predictionalgorithms are also applied to determine if collisions will occur.

Step 14: Re-selecting ports based on validation. If port placementsand/or robot positioning fail the validation step, the port/positioningcombination is rejected and steps 11 through 13 are repeated to choosenew port placement locations and/or robot positions.

Step 15: Simulating surgical procedure. Step 15 involves performinginteractive surgery rehearsal by the surgeon, including surgeon inputsfor simulated robotic manipulations, applying collision predictionalgorithms, and/or inputting surgeon subjective assessment ofeffectiveness.

Step 16: Re-selecting ports based on simulation. If simulation isunsatisfactory, port placements and/or robot positioning may be rejectedand steps 11 through 15 may be repeated to select and validate newplacements and/or positions. Optionally, if simulation isunsatisfactory, the surgeon may fix one or more of current ports, and/orpre-select one or more ports, based on simulation/rehearsal experience(e.g., A desirable tool or endoscope port), and repeat steps 11-15 tore-optimize with reduced feasible port set.

Step 17: Recording and analyzing simulation data. Recorded simulationhistory and computer data, including surgeon inputs, tool motions androbotic arm movements, may be used to refine models, optimizationcriteria, feasibility criteria and/or cost function terms.

Step 18: Repeating steps 8-17 for additional targets. For complex ormulti-site procedures, planning steps may be repeated for all necessarysurgical targets.

Step 19: Determining multi-target optimized robotic system base supportposition.

Optionally, method steps may be employed to optimize the base positionof a robotic system to permit advantageous access to all targets.Preferably, the robotic system base support(s) are pre-positioned sothat the multi-target procedure may be performed with no re-positioningof base support(s).

Step 20: Multi-target port optimization. Optionally, method steps may beused to re-optimize port triplets to use particular ports for more thanone target (minimize total number of ports and reduce set up time whenaccessing multiple targets).

Step 21: Transferring and registering planning results to patient bodyand surgical system. For both robotic and non-robotic surgicalprocedures, the results of planning are transferred to the patient. Themodel of the planned procedure may be registered to the patient's bodyin the operating room. Transfer and registration may include the markingof port locations, and reproducing the planned initial positions andalignment of the instruments and/or robotic arms. For example, thefollowing sub-steps may be used:

1. selecting common reference point(s) and/or directional bearing forpatient on operating table and for models (robotic and patient models);

2. superimposing alignment of models to patient coordinates;

3. aligning the robotic system to the reference point(s) and bearings;

4. determining actual ort locations based on model relative to patientcoordinates; and

5. making incisions at determined port locations for instrumentinsertion.

Optionally, a robotic control system, joint position sensors andencoders may be employed to effect a transformation from patientreference coordinates to joint-space coordinates for the robotic system.In one embodiment, for example, a robotic arm may be positioned to touchone or more reference point(s) on the body surface. Robotic systemcoordinates may then be defined relative to the body reference point(s).Finally, joint position sensors may monitor the arm motions relative tothe body reference point(s), to direct and/or confirm setup armpositioning according to the optimized procedure plan, and to directand/or confirm instrument orientation and tip location to touch the bodysurface at a modeled port location and orientation.

Step 22: Collision detection during surgical procedure. Optionally, thecollision prediction/detection algorithms may be applied to real-timerobotic arm and instrument positions and orientations to predict, warnof, and/or avoid collisions during the procedure.

Step 23: Recording and analyzing operational data. Recorded procedurehistory and computer data, including surgeon inputs, tool motions androbotic arm movements, may be used to refine models, optimizationcriteria, feasibility criteria and/or cost function terms. The roboticsurgical system may be provided with an Application Program Interface(API), or the equivalent, in communication with the robotic controlsystem and/or endoscope imaging system, to permit recordation during thecourse of a surgical procedure (and/or real-time analysis) of sensorsignals, encoder signals, motions, torques, power levels, rates, inputcommands, endoscope display images, and the like.

While the above is a complete description of exemplary embodiments ofthe invention, various alternatives, modifications and equivalents maybe used. For example, various steps or stages in any of the abovemethods may be combined. For example, in one embodiment the planning andvalidation steps may be combined. In other embodiments, steps may beadded or eliminated.

As described variously above, methods and apparatus of the presentinvention are not limited to robotic surgery, but may be applied tolaparoscopic, minimally invasive, or other types of surgery.Furthermore, the present invention is not limited to any particular typeor category of surgical procedure. Examples of surgical procedures(including veterinary surgical procedures) in which embodiments of theinvention may be used include, but are not limited to robotic andnon-robotic thoracic, abdominal, neurological, orthopedic,gynecological, urological surgical procedures, and/or the like. Thesurgical instruments and instrument combinations employed may includemore than one endoscope, or may include an integrated multifunctionalendoscope/tool. Likewise the instrument combinations may includeinterventional instruments used with or monitored by other modalities ofmedical imagery instead of, or in addition to, visual endoscopy, e.g.,ultrasound, real-time MRI, CT, fluoroscopy, and the like

When applied to robotic surgery, embodiments having aspects of theinvention are not limited to any particular make or type of roboticsurgical system. Thus, methods and apparatus according to the principlesof the invention may include robotic systems having more or fewer thanthree robotic arms, surgical procedures employing two or morecooperative robotic systems, robotic surgical systems cooperated by twoor more surgeons simultaneously, or the like. Embodiments having aspectsof the invention may include surgical systems having passivecenter-of-motion robotic manipulators, computed center-of-motion roboticmanipulators, and/or mechanically constrained remote center-of-motionrobotic manipulators, and the like. Models of robotic systems employedin simulation and planning steps may include modeling of activemanipulator links and joints (servo-operated and passively respondingjoints which move during tissue treatment operation). Robotic arm modelsmay also include base support links and joints (set up orpre-positioning arms fixed during tissue treatment operation).Multiple-arm robotic systems employed in embodiments having aspects ofthe invention may include a plurality of robotic arms may have a singleintegrated support base (e.g., a multi-arm cart-type support base), oreach arm may have an individual base (e.g., wherein each robotic arm isindividually clamped to an operating table structure or rail), orcombinations of these.

Additionally, the present invention is not limited to surgicalprocedures on a human patient or animal patient, but may be employed ina variety of non-surgical or quasi-surgical procedures and operations.The principles of the invention are particularly suitable to operationsusefully performed by remotely operated or robotic tools, wheresubstantially similar modeling, planning and simulation methods areuseful. Examples include operations on a defined target volume, such asdeactivation of a suspected explosive device; remote inspection andoperations within a container, vehicle, or the like; underwateroperations; and rescue operations in a collapsed structures, mine andthe like. In non-surgical and quasi-surgical target volumes, themodeling of the target volume may optionally be based, at least in part,on archival data, such as engineering data, architectural data, CAD fileinputs, and the like, as well as a variety of different activelyacquired data modalities.

Therefore, the above description should not be taken as limiting thescope of the invention which is defined by the appended claims.

1. (canceled)
 2. A method for identifying advantageous locations for twoor more entry ports for performing a robotic surgical procedure on abody of a patient, the method comprising: identifying a plurality ofport optimization criteria; assigning numerical values to the portoptimization criteria associated with each of at least two candidateport arrangements; computing a cost metric for each candidate portarrangement, the cost metric comprising a weighted combination of thenumerical values assigned to the port optimization criteria for thatcandidate port arrangement; and selecting the candidate port arrangementhaving an optimal value of the cost metric.
 3. The method as in claim 2,wherein the plurality of criteria includes at least one of robotkinematics, robot kinetics, robot work range, deviation of tool entryangle from normal, organ geometry, surgeon defined constraints, robotforce limitations, and patient force limitations.
 4. The method as inclaim 2, wherein the plurality of criteria includes at least one of adeviation from a desired configuration, arm placement symmetry withrespect to endoscope positioning, and tool entry angle with respect tosurface normal.
 5. The method as in claim 2, the assigning numericalvalues comprising employing imaging data acquired using at least one ofcomputed tomography, magnetic resonance imaging, conventionalradiography, and arterial angiography.
 6. The method as in claim 2,further comprising determining positions for robotic arms individuallyholding one of a triplet of medical devices for insertion into threesurgical entry ports.
 7. The method as in claim 6, wherein thedetermination of the positions of the robotic arms is based at least inpart on a set of criteria, the criteria including at least one of robotkinematics, robot kinetics, robot work range, deviation of tool entryangle from normal, organ geometry, surgeon defined constraints, robotforce limitations, and patient force limitations.
 8. The method as inclaim 2, further comprising: preparing a representation of a definedvolume within the patient from a set of acquired data; and facilitatinga first simulation for enabling a user to simulate a medical procedureperformed through said surgical entry ports, the first simulation basedupon the representation of the defined volume, the advantageouslocations of the entry ports, and a surgical protocol.
 9. The method asin claim 8, further comprising: enabling the user to reject one or moreof the advantageous locations based on the first simulation; determiningdifferent advantageous locations based on the user's rejection; andfacilitating a second simulation for enabling the user to simulate themedical procedure, the second simulation being based upon the model ofthe defined volume, the different advantageous locations of the entryports, and the surgical protocol.
 10. The method as in claim 2, furthercomprising storing information of the advantageous locations in amemory.
 11. An apparatus for identifying advantageous locations for twoor more entry ports for performing a robotic surgical procedure on abody of a patient, the apparatus comprising a tangible medium configuredwith machine readable code to: identify a plurality of port optimizationcriteria; assign numerical values to the port optimization criteriaassociated with each of at least two candidate port arrangements;compute a cost metric for each candidate port arrangement, the costmetric comprising a weighted combination of the numerical valuesassigned to the port optimization criteria for that candidate portarrangement; and select the candidate port arrangement having an optimalvalue of the cost metric.
 12. The apparatus as in claim 11, wherein themachine readable code is further configured to determine a preferredposition for placement of a robotic apparatus relative to the pluralityof surgical entry ports.
 13. The apparatus as in claim 11, wherein theplurality of criteria includes at least one of robot kinematics, robotkinetics, robot work range, deviation of tool entry angle from normal,organ geometry, surgeon defined constraints, robot force limitations,and patient force limitations.
 14. The apparatus as in claim 11, whereinthe plurality of criteria includes at least one of a deviation from adesired configuration, arm placement symmetry with respect to endoscopepositioning, and tool entry angle with respect to surface normal. 15.The apparatus as in claim 11, the machine readable code configured toassign numerical values by employing imaging data acquired using atleast one of computed tomography, magnetic resonance imaging,conventional radiography, and arterial angiography.
 16. The apparatus asin claim 11, the machine readable code further configured to determinepositions for robotic arms individually holding one of a triplet ofmedical devices for insertion into three surgical entry ports.
 17. Theapparatus as in claim 16, wherein the determination of the positions ofthe robotic arms is based at least in part on a set of criteria, thecriteria including at least one of robot kinematics, robot kinetics,robot work range, deviation of tool entry angle from normal, organgeometry, surgeon defined constraints, robot force limitations, andpatient force limitations.
 18. The apparatus as in claim 11, the machinereadable code further configured to: prepare a representation of adefined volume within the patient from a set of acquired data; andfacilitate a first simulation for enabling a user to simulate a medicalprocedure performed through said surgical entry ports, the firstsimulation based upon the representation of the defined volume, theadvantageous locations of the entry ports, and a surgical protocol. 19.The apparatus as in claim 18, the machine readable code furtherconfigured to: enable the user to reject one or more of the advantageouslocations based on the first simulation; determine differentadvantageous locations based on the user's rejection; and facilitate asecond simulation for enabling the user to simulate the medicalprocedure, the second simulation being based upon the model of thedefined volume, the different advantageous locations of the entry ports,and the surgical protocol.
 20. The apparatus as in claim 11, the machinereadable code further configured to store information of theadvantageous locations in a memory.
 21. A robotic surgical systemcomprising: first and second robotic arms adapted to respectively holdfirst and second surgical tools for performing a medical procedure on apatient; a third robotic arm adapted to hold an image capturing device,and a computer for selecting a preferred arrangement of entry ports forthe first and second robotic arms from among at least two candidate portarrangements, the computer configured to: identify a plurality of portoptimization criteria; assign numerical values to the port optimizationcriteria associated with each candidate port arrangement; compute a costmetric for each candidate port arrangement, the cost metric comprising aweighted combination of the numerical values assigned to the portoptimization criteria for that candidate port arrangement; and selectthe candidate port arrangement having an optimal value of the costmetric as the preferred arrangement of the plurality of surgical entryports.